Yet some men do, willingly. (just all the new ones better look like daddy!)
Who knows what was done in prehistory, during ages or in cultures where resources were SO scarce that only ones own children were provided for?
I think societies worked that out case by case. I remember reading that some tribes regarded the widow of your brother as your own wife and HIS children would be YOUR responsibility as well as your own.
Even today in the Orthodox faith, godparents represent something more than an honorific status. I was and is STILL done with the expectation that, as in older times, godparents provide for the child in case parents are lost.
There are a lot of men, today, who struggle for children not his own, and do it at the point of a gun.
It’s benignly called “transfer benefits”.
Seems the Ghetto displays the opposite. They all want to be babby daddys to a dozen Ho’s.
Also, if this is an overriding instinct enough to cause man to become monogamous, why do Homosexuals persist, and also desire marriage?
Three obvious examples in action today that the theory ignores to speculate in things long past defining the present.